Two studies published this week highlight the impact that volcanic eruptions may have on climate, both on short (a few years) and long (millions of years) time scales.
BBC posted an article on some recent research by Dutch scientists suggesting that an eruption of Mt. Chichon in Mexico in the 6th century can be linked to a disruption in Mayan civilization. This eruption, which occurred around 540 AC, was much larger than the eruption of 1982. You can read it at https://www.bbc.com/news/science-environment-36086096.
A separate article published by the University of Texas described “a new study in the April 22 edition of Science [which] reveals that volcanic activity associated with the plate-tectonic movement of continents may be responsible for climatic shifts from hot to cold over tens and hundreds of millions of years throughout much of Earth’s history.” This may help explain long-term shifts in climate in addition to changes due to solar radiation variations associated with changes in the earth’s orbit around the sun, which work more on a 100,000 year time scale.